In a decision last week, the Federal Circuit construed the scope of § 121's allowances for subsequent patent applications directed toward nonelected inventions in response to a restriction requirement. There were three patents at issue, one directed to pharmaceutical compounds, one to compositions containing those compounds, and a third covering methods of suing the compounds. The method of use patent was derived from a continuation-in-part application filed after a restriction requirement in the original application. The district court held that notwithstanding how the application was styled, it was entitled to the original application's priority date.
The Federal Circuit disagreed, holding that § 121, by its terms, is limited to divisional applications. As a result, the method of use patent was not entitled to the earlier filing date, and was invalid for obviousness-type double patenting based on the composition patent. The court affirmed the district court's findings that the best mode requirement was not violated and that no inequitable conduct had occurred.
More detail of Pfizer, Inc. v. Teva Pharms. USA, Inc. after the jump.
Pfizer produces and sells the drug Celebrex, a non-steroidal anti-inflammatory drug ("NSAID") for the treatment of osteoarthritis and rheumatoid arthritis. Pfizer owns three patents related to Celebrex. The first claims both a broad genus of NSAIDs as well as Celebrex's active ingredient, celecoxib. The second claims compositions using those compounds and the third claims methods of their use.
Teva, a generic drug manufacturer, filed an Abbreviated New Drug Application (ANDA) with the FDA addressed to a proposed drug identified as celecoxib capsules. Pfizer filed suit, alleging that Teva's ANDA filing was an act of patent infringement. In its answer, Teva did not argue that its ANDA was not within the scope of the claims, but instead asserted affirmative defenses that the patents-in-suit were invalid or unenforceable.
The district court rejected each of Teva's invalidity arguments and found Pfizer's patents valid and infringed. The district court first rejected Teva's defense that the asserted patents were invalid as obvious over the prior art, which was not appealed by Teva. The district court likewise rejected Teva's best mode defense as to all of the asserted patents, and determined that no inequitable conduct had taken place.
The court also rejected Teva's double patenting argument, which was based on the theory that the composition patent was prior art to the method of use patent because the method of use patent was filed as a CIP, not a divisional, and thus was not entitled to the earlier application's filing date under § 121. In this regard, the court noted that both patents were derived from applications filed in response to a restriction requirement made in the common parent application, and as a result, were not prior art to each other.
On appeal, the Federal Circuit first considered the issue of obviousness-type double patenting of the method patent in view of the composition patent claims. Teva contended that § 121 applies exclusively to divisional application, and that because the method patent issued from a CIP rather than on a divisional application, it did not fall within the terms of the statute. In response, Pfizer argued that although the application that led to the method patent was termed a CIP, it was still in effect a "divisional application" as the term is used in § 121 because § 121 refers broadly to any type of application filed as a result of a restriction, regardless of whether it is labeled by the PTO, for administrative purposes, as a divisional, a continuation, or a CIP. The relevant portion of § 121 reads:
A patent issuing on an application with respect to which a requirement for restriction under this section has been made, or on an application filed as a result of such a requirement, shall not be used as a reference either in the Patent and Trademark Office or in the courts against a divisional application or against the original application or any patent issued on either of them, if the divisional application is filed before the issuance of the patent on the other application.The Federal Circuit agreed with Teva. The court noted there was no suggestion in the text or legislative history of § 121 that the safe-harbor provision was, or needed to be, directed at anything but divisional applications. The court surmised that the reason for this was that the need for the safe-harbor protection provisions of § 121 existed when a divisional application was filed as a result of the restriction. Otherwise, if the section had included CIPs, which by definition contain new matter, the section might be read as providing the earlier priority date eve as to the new matter, contrary to the usual rule that new matter is not entitled to the priority date of the original application. The court therefore concluded that the protection afforded by § 121 to applications filed as a result of a restriction requirement is limited to divisional applications.
Because § 121 did not apply, the court then had to determine whether the claims of the two patents were patentably distinct. The court noted that the claims at issue of the method patent merely recited methods of administering a "therapeutically-effective amount" of the compositions found in the composition patent. Thus, the court determined the claims were not patentably distinct, and accordingly held the asserted claims of the method patent were invalid for obviousness-type double patenting.
With regard to the best mode requirement, the court noted that the best mode requirement does not demand disclosure of every preference an inventor possesses as of the filing date, but instead requires the inventors "to disclose aspects of making or using the claimed invention [when] the undisclosed matter materially affect[s] the properties of the claimed invention." Teva contended that Pfizer violated the best mode requirement during prosecution of the composition patent by failing to disclose its preference for compounds having COX-2 selectivity. Pfizer argued that disclosure of such a preference was not required under the best mode requirement on the basis there was no dispute that one of ordinary skill in the art would have known how to make and use the claimed compositions and compounds themselves. The court agreed with Pfizer, holding that at least the celecoxib-specific claims infringed by Teva were not invalid, and because dosage information was disclosed in the patent, knowledge of the selectivity was not necessary to arrive at a proper dosage.
Finally, the court addressed Teva's argument that Pfizer had committed inequitable conduct by failing to disclose the two Merck publications during the prosecution of the applications leading to the patents in suit. Both publications derived from and claimed priority to an unpublished Merck application filed several months before Pfizer filed its initial application, and it was undisputed that Pfizer knew of the references. Teva relied on the materiality of the two references to support a finding of intent to decieve, however Pfizer offered a plausible reason for not disclosing the references, namely that Pfizer had studied the references and determined that the disclosed compounds were not sufficiently similar, as they had different heterocyclic core than the compounds in the Pfizer applications. The court concluded that even if the Merck references were material, the district court did not clearly err in finding that Teva failed to establish that Pfizer acted with an intent to deceive, and affirmed the district court's finding.
This case provides a warning that when pursuing claims that were subject to a restriction requirement in a subsequent application, prosecutors should be certain to file the subsequent application as a divisional application (as opposed to any other type) in order to ensure that the "safe harbor" of § 121 will be available.
To read the full decision in Pfizer, Inc. v. Teva Pharms. USA, Inc., click here.